The invention relates to a method for connecting a wire cable to a cable shoe for a belt buckle mounting. The invention further relates to an apparatus for connecting a wire cable to a cable shoe for a belt buckle mounting.
In particular the belt buckles for the back seat of an automotive vehicle are attached directly or indirectly to the car body with the aid of wire cables so that the belt buckles exhibit certain mobility. Even when so called linear tensioners are used, the belt buckles are fastened to wire cables, the wire cable further being connected to the piston of the linear tensioner.
From DE 10 2007 012 039 A1 a cable shoe is known by which one end of such wire cable can be connected to a belt buckle, fittings or the car body. The cable shoe is a punched sheet metal part having a fastening portion serving for fastening the cable shoe to the belt buckle, the fittings or the car body and having a retaining portion forming in a pre-bent state an eye into which the wire cable is inserted. The retaining portion includes two rims a first rim of which includes projections with a lateral thickening and the second rim includes corresponding recesses with an undercut. In the pre-bent state of the retaining portion the projections of the first rim engage in the recesses of the second rim. The retaining portion is pressed after inserting the wire cable so that the outer periphery of the eye is reduced and thus the wire cable is clamped.
Ideally the caught rims of the retaining portion are intended to form a continuous smooth surface after extrusion so that no gap and no overlapping are provided between the projections and the recesses. When force is applied to the wire cable, the projections and the recesses cannot move against each other so that the eye remains safely closed and the wire cable cannot be removed from the cable shoe.
Due to the high requirements to the load capacity of such cable connection—even with respect to the use of the cable shoe in a belt tensioner when very high tensile forces act on the wire cable—extrusion of the retaining portion has to be performed with extremely high pressure, which entails rapid wear of the pressing tool.